HOUSTON — Former President George Bush and his wife, Barbara, were among the mourners Wednesday at a memorial service for Enron Corp. founder Kenneth Lay.

Lay’s memorial drew some of the high-profile guests who were close to him before he was convicted in May of fraud and conspiracy for lying to investors and the public about the energy company’s financial health before it collapsed in 2001.

Among the other mourners at the downtown Houston church Lay attended for 12 years were former Secretary of State James A. Baker III, Houston Astros owner Drayton McLane Jr., heart surgeon Denton Cooley and Lay’s criminal lawyer, Mike Ramsey.

Former Houston Mayor Bob Lanier, 81, collapsed at the memorial service shortly after arriving and was taken by ambulance.

“He was very, very ill,” said Pastor Steve Wende, officiating at the service, held a few blocks from the glittering towers that once were the Enron buildings.

Lay, 64, died July 5 while vacationing in Aspen, Colo. with his wife, Linda. About 200 friends and family attended a memorial service Sunday in the ski resort town.

Lay and former Enron CEO Jeffrey Skilling were convicted in May of perpetuating fraud by repeatedly lying to investors and employees about the company’s financial health before Enron careened into bankruptcy proceedings in December 2001.

Skilling, 52, attended the Aspen service and planned to attend Wednesday’s service in Houston as well, said his attorney, Daniel Petrocelli. It was not immediately clear whether Skilling was at the memorial, which he had planned to attend.

The two men were the public faces of Enron throughout its days as a premier trading company that enjoyed Wall Street’s adoration and grew into the nation’s seventh-largest company. They also fell hard, vilified as masterminds of a massive fraud that fueled a flameout that left thousands jobless and wiped out billions from investors.

They insisted at their trial that they committed no crimes and no fraud occurred at Enron except for a few executives who skimmed money behind their backs.

A jury convicted Lay of six counts of fraud and conspiracy and Skilling of 19 of 28 counts of fraud, conspiracy, insider trading and lying to auditors. Lay also was convicted of bank fraud and lying to banks in a separate, non-jury trial related to his personal banking.

Little mention was made of Enron during Lay’s Aspen service. Before Enron crashed, Lay was a highly respected business leader and philanthropist in the nation’s fourth-largest city with a powerful circle of friends that included Bush as well as his son, the current president.

Security was tight for the Aspen service, and attendees were allowed in only if their names appeared on the guest list. But security won’t be as stringent at Wednesday’s service in a much larger sanctuary that can seat up to 1,500.

Kimberly said Tuesday that the service was open to friends and family, and attendees didn’t have to be on a guest list to be admitted. But media will remain barred from the service.

Allen Houk, communications director for the church, added that no cameras or recording devices will be allowed on church property. He said uniformed police officers would be on hand to maintain the electronics ban.